The present invention relates to gas turbine engines and particularly to engine thrust bearing condition associated with the gas turbine engines.
Industrial engines on occasion can exhibit catastrophic secondary engine damage upon incurring engine thrust bearing failure. Failures of thrust bearings can jeopardize the serviceability of engine high pressure turbine and compressor airfoils. This is particularly true when thrust bearing failure detection and subsequent engine shutdown measures are not immediately executed.
General industry practice has been to monitor bearing lubrication supply and scavenge temperatures. Another form of protection is a chip detection system located at bearing scavenge lines. These systems monitor the level of particles released by the bearing or associated sump hardware. These methods of protection primarily provide alarm and trip commands to the control system. An xe2x80x98alarm onlyxe2x80x99 mode permits an operator to acknowledge and correct the detected fault by reducing engine load level. However, during extended engine operating periods, subsequent to thrust bearing failure, catastrophic secondary damage can occur as scavenge temperature rises very rapidly.
It would be desirable, then, to be able to monitor engine thrust bearing temperature using a predicted sump temperature change to prevent catastrophic secondary engine damage.
The present invention proposes to utilize various measured engine parameters to predict sump temperature rise, and then use the predicted sump temperature rise to monitor engine thrust bearing temperature. The predicted sump temperature rise is compared to the actual measured bearing temperature, and when the difference is greater than a predetermined value, the engine control system can automatically shut the engine down. This would prevent a catastrophic engine failure.
A method is provided for monitoring engine thrust bearing temperature deviations. Initially, key engine parameters are measured. A bearing temperature rise can be predicted based on the measured parameters. The predicted rise value is compared with the actual, measured, rise value to generate a comparison value. The system is trained to respond to the comparison value to prevent catastrophic failure.
Accordingly, the present invention provides an effective technique for monitoring engine thrust bearing temperature using a predicted sump temperature rise. The capability of predicting sump temperature rise and automatically tripping the engine can prevent a catastrophic engine failure. Furthermore, this reduces engine rebuild costs and downtime.